Pacheco’s Dosease

Pacheco’s disease is a highly infectious and deadly bird illness. It is caused by the rapidly spreading Herpesvirus and especially affects birds in the parrot family. Once infected, the animal may or may not develop symptoms, but usually dies within a few days of contracting the disease.
Pacheco’s disease damages many of the bird’s organs, including the liver, spleen, and kidneys. If the bird does survive an infection, however, the organ damage will remain permanent.

The main symptoms of Pacheco’s disease are: 
– Green colored feces, due to liver damage
– Listlessness
– Diarrhea
– Nasal discharge
– Lack of appetite
– Swelling
– Redness of eyes
– Tremors
– Ruffled feathers

And while these signs usually appear within three to seven days of infection, not all birds will display symptoms.
Herpes virus causing Pacheco’s disease in liver tissues

Pacheco’s disease is caused by the herpesvirus, usually contracted from the feces and nasal discharges of other infected birds. Feather dust, dander, and contaminated air, food, water and living surfaces also help spread this deadly disease. Stress due to losing a mate, breeding, relocation, climate changes and other environmental and emotional changes, can trigger the infection, as well.

It is important to note the Pacheco’s disease herpesvirus can survive outside the bird’s body for a long time, and thus infect a bird from any contaminated surface.

A veterinarian will generally prescribe Acyclovir for Pacheco’s disease. However, the medication is known to cause kidney damage, and works best during the initial stages of the infection, before the symptoms show.


If your bird does contract Pacheco’s disease and survives, stress may trigger the infection to resurface. Therefore, it is important to quarantine any birds suspected of having this virus for one to two months, and ensure it is not spread to any other animals.

All contaminated surfaces should then be disinfected with an oxidizer, like chlorine bleach. All air filters in the home should also be replaced.

It is important birds have regular testing. Vaccinations are available in two-dose injections and are given to the infected birds in four-week intervals. After which, one booster dose is needed annually. However, the vaccine has been reported to have side effects, and only birds at risk — like pet store birds — should be vaccinated.